Device for cooling of heat-generating units

ABSTRACT

The present invention relates to a method and an apparatus for cooling heat generating units, such as mobile telephone equipment in a radio base station. By providing a heat exchanger ( 69 ) having crossing flow directions for an internal vertical air flow ( 76 ) and external lateral, cooling air flows ( 70, 73 ) in a vertical area, such as a wall portion to the radio base station, for instance as a part of a door to the radio base station, excellent cooling may be achieved without substantially affecting the space by means of the heat exchanging function, which is intented for the equipment.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a method for cooling heat generating units in for instance radio base stations, and an apparatus for cooling heat generating units in for instance radio base stations. A radio base station comprises a lot of heat dissipating units.

STATE OF THE ART

[0002] Telephone equipment located in closed spaces release heat during its operation. This process is continuously in progress and the temperature around the equipment must be kept within certain limits. Particularly, it is of great importance that a specified maximum temperature is not to be exceeded. Usually, mechanical cooling system, such as compressor operated evaporation systems are used to manage cooling and temperature control. In these systems hot indoor air is passing through an evaporator so as to cool it. The cooled air is then recirculated to the space. Continuous heat dissipation require continuous cooling. Prior art documents, such as U.S. Pat. No. 3,559,728, DE-C2-3 044 135, DE-C1-4 134 429 and Ericsson Review, ERA, no. 9, 82-10-01, page 24-26 “Klimatisering av apparatskåp” show how electronics enclosed in a space may be cooled by means of interchange of heat, i.e. letting cold outdoor air flows cool hot indoor air flows in a heat exchanger.

SUMMARY OF THE INVENTION

[0003] To cool telephone equipment in outdoor cabinets, such as a mobile telephone equipment in a radio base station cooling is required, which preferably is taken from the atmosphere surrounding the radio base station. By arranging at least one heat exchanging function with crossing air flow directions in a vertical area, such as a wall portion of the radio base station, for example constituting a part of a door of the radio base station, between at least one internal vertical air flow and at least one cooling, from the side flowing, external air flow, excellent cooling of the equipment may be achieved, without substantially affecting the space intended for the equipment due to the presence of the heat exchanging function. By arranging the heat exchanging function in an openable door for the space intended for the equipment, the components of the heat exchanging function may easily be mounted, repaired and cleaned.

[0004] The invention will now be more closely described by means of preferred embodiments and with reference to appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 shows an internal view of a climate module according to the invention for support by e.g. a door.

[0006]FIG. 2 shows an external view of the climate module in FIG. 1.

[0007]FIG. 3 shows an internal view of the climate module in FIG. 2 with stated flow directions.

[0008]FIG. 4 shows an internal view of an alternative climate module according to the invention for support by a door.

[0009]FIG. 5 shows an external view of the climate module in FIG. 4.

[0010]FIG. 6 shows an internal view of the climate module in FIG. 4 with stated flow directions.

[0011]FIG. 7 shows an internal view of yet a climate module according to the for support by a door.

[0012]FIG. 8 shows an external view of the climate module in FIG. 7.

[0013]FIG. 9 shows an internal view of the climate module in FIG. 8 with stated flow directions.

PREFERRED EMBODIMENTS

[0014] In FIGS. 1 and 2 a so called climate module 1 is shown, and how such a climate module is to be arranged for cooling a radio base station. Preferably, the climate module will be placed as a unit on an inner side of a door of the radio base station, wherein the climate module is adapted as a heat exchanger, so as to cool an indoor air flow by means of an outdoor air flow originating from the surrounding atmosphere, wherein the cooled indoor air is used for cooling heat generating units in the radio base station. Preferably, on the inner side of the door, see FIG. 1, the climate module 1 is arranged, and on which inner side an opening 2 is located at an upper part, for intake of heated indoor air 3, and at a lower part an opening 4 is located, for exhaust of cooled indoor air 5, whereby parts of a fan 6 for intake of heated indoor air and exhaust of cooled indoor air are shown. On the outside of the climate module, see FIG. 2, an opening 7 is located at an upper part, for intake of cold outdoor air 8 intended for heat exchange, and an opening 9 for exhaust of, by indoor air heated through said heat exchange, outdoor air 10. In a lower part of the climate module an opening for exhaust of outdoor air 12 is provided, which outdoor air 12 is heated by means of heat exchanged indoor air, and an opening 13 for intake of cold outdoor air 14 intended for heat exchange. In the openings intended for intake of cold outdoor air, parts of intake fans 15, 16 are indicated. In FIG. 3 an external view of the climate module is shown, where a cover at the door side is removed, so as to show how the various air flows are acting inside the climate module. At an upper part of the climate module an outdoor air flow 17 is crossing, in a heat exchanger 18, heated indoor air 19 from right to left. At a lower part, an outdoor air flow is crossing, in a heat exchanger 21, the heated indoor air from left to right. In spaces 22, 23 adapted for intake of outdoor air the intake fans 15, 16 are mounted on beams 24, 25 connecting the upper side and the lower side of the climate module, respectively with an intermediate partition element 26. By means of the intake fans 15, 16 cold outdoor air is drawn into and forced through the heat exchangers 18, 21, and the heated outdoor air is collected in spaces 27, 28 within the openings 9, 11 for exhaust of the heated outdoor air. In the centre of the upper part of the climate module the opening 2 for intake of heated indoor air is shown, and in the centre of the lower part the intake fan 6 for the heated indoor air is shown. The horizontal arrows 17, 20 show the flow directions of the cold outdoor air through the heat exchangers 18, 21 from the intake fans 15, 16 to the outlet chambers 27, 28. The vertical arrow 19 shows the flow direction of the heated indoor air through the heat exchangers 18, 21 from the inlet opening 2 to the intake fan 6.

[0015] In FIG. 4 an interior view of the climate module 29 is shown, which is similar to the climate module shown in FIGS. 1-3, and being provided with a sealing cover 30. Also, this type of heat exchanger may be arranged on the inner side of a door of e.g. a radio base station. Heated air 31 from the various units in the radio base station is drawn into an opening 32 in the upper part of the module and is then exhausted, cooled 33 by outdoor air, from an opening 34 in the lower part of the module, which may be provided with guiding ribs so as to achieve some guidance of the cooled indoor air leaving the module. In FIG. 5 an external view of the box-like module 29 is shown, comprising two cooling air intakes 35, 36 arranged on a first side of the module in connection with intake fans 37, 38 for cooling air 42, and two outlet chambers 40, 41 for heated cooling air 43, are arranged on the second side. At a lower portion the location of an intake fan 44 is indicated. In FIG. 6 an internal view of the flow directions through the climate module 29 having the cover 30 removed are shown. The horizontal arrows 45, 46 show the flow directions through the heat exchangers 47, 48 of the cooling air flows, from the intake fans 37, 38 at the right, to the outlet chambers 40, 41 at the left. A vertical arrow 49 shows a flow direction of a heated air flow from the upper inlet opening 32, through the heat exchangers 47, 48, to a lower outlet opening 50, in which the intake fan 44 is arranged. The intake fans 37, 38 for the outdoor air are arranged on respective cross bars 52 against the cover. In this embodiment, the outlet chamber 34 for the cooled indoor air requires a greater portion of the lower part of the module, which together with the guiding ribs result in a directed cooling air flow for the interior units accommodated in for instance a radio base station.

[0016] In FIG. 7 yet an example of a climate module 53 adapted for heat exchange is shown, which is to be mounted on e.g. the inner side of a door of a radio base station, so as to cool the various units within the radio base station. At an upper, inner part of the climate module an inlet opening 54, and behind this opening, an intake fan 55 are located for intake of hot indoor air 56, and at a lower part an outlet opening 57 for cooled indoor air 58 is located. In FIG. 8 an external view of the climate module is shown having, at a lower portion, two inlet openings 59, 60 being provided with intake fans 61, 62 for cold outdoor air 63, 64 and at an upper portion, two outlet openings 65, 66 for heat exchanged outdoor air 67, 68. The cold outdoor air 63, 64 is drawn into the climate module, e.g. by means of the fans through a grate in the door side, which then force the cold air, from two directions, through a heat exchanger, whereupon the outdoor air leaves the heat exchanger and continuous out via the outlet openings 65, 66. In FIG. 9 the flow directions through the heat exchanger are shown. An arrow 70 shows the flow direction of the cold outdoor air from a lower intake chamber 71 at the left, through the heat exchanger 69, and further on to an upper outlet chamber 72 at the right. An arrow 73 shows the flow direction of the cold outdoor air from a lower intake chamber 74 at the right, through the heat exchanger 69, and further on to an upper outlet chamber 75 at the left. A vertical arrow 76 shows the flow direction of the heated indoor air from the intake fan 55, through the heat exchanger 69, to the lower outlet chamber 57. By letting two cold sides run crosswise through the heat exchanger a great temperature gradient is achieved between the hot and the cold sides of the heat exchanger.

[0017] By measuring and registering the temperature of the indoor air and the outdoor air, at the same time as at least one, or both, of the fans for the indoor air and the outdoor is controllable, a supervisory unit 77 may control, by means of detecting temperatures 78, 79, the speed of revolution of at least one of the fans, so as to achieve an optimal cooling of the enclosed heat generating electronics.

[0018] The invention is of course not limited to the above described, and on the drawing shown embodiments, but can be modified within the scope of the appended claims. 

1. Climate module to be arranged in a wall- or door portion of an outdoor cabinet for cooling heat generating units enclosed in said outdoor cabinet, comprising at least: a first and a second heat exchanger (18, 21; 47, 48) adapted for heat exchange between internal and external air flows (19, 17, 20; 49, 45, 46), whereby the internal air flow (19; 49) is adapted to be taken from and be returned to the outdoor cabinet, and a first and a second external air flow (17, 20; 45, 46) are adapted to be taken from and be recirculated to outdoor air, characterised in that the first heat exchanger (18, 47) is arranged in series with the second heat exchanger (21, 48) with respect to the internal air flow (19; 49), and the first heat exchanger (18, 47) is arranged in parallel with the second heat exchanger (21, 48) with respect to the first and second external air flows (17, 20; 45, 46).
 2. Climate module according to claim 1, wherein the first external air flow (17; 45) is adapted to flow through the first heat exchanger (18; 47), and the second external air flow (20; 46) is adapted to flow through the second heat exchanger (21; 48).
 3. Climate module according to claim 2, wherein the first external air flow (17; 45) is counter-current the second external air flow (20; 46).
 4. Climate module according to any of claim 1-3, wherein the internal air flow (19; 49) is adapted to flow vertically through the first and second heat exchanger (18, 21; 47, 48), while the first and second external air flows (17, 20; 45, 46) are adapted to flow horizontally through the first and second heat exchanger (18, 21; 47, 48).
 5. Climate module according to any of claim 1-4, wherein the first heat exchanger (18; 47) comprises an inlet opening (2; 32) for the internal air flow (19; 49), an inlet opening (7; 35) for the first external air flow (17; 45), and an outlet opening (9; 40) for the first external air flow (17; 45), and the second heat exchanger (21; 48) comprises an outlet opening (4; 34) for the internal air flow (19; 49), an inlet opening (13; 36) for the second external air flow (20; 46) and an outlet opening (11; 41) for the second external air flow (20; 46).
 6. Climate module according to any of claim 1-5, wherein at least one fan (6; 44) is provided for the internal air flow (19; 49) for intake to, passage through, and exhaust from, the first and the second heat exchanger (18, 21; 47, 48).
 7. Climate module according to any of claim 1-6, wherein at least one fan (15, 16; 37, 38) is arranged for the first and second external air flows (17, 20; 45, 46) for intake to, passage through, and exhaust from, the first and the second heat exchanger (18, 21; 47, 48). 